scholarly journals Diffusion-weighted magnetic resonance spectroscopy enables cell-specific monitoring of astrocyte reactivity in vivo

2018 ◽  
Author(s):  
Clémence Ligneul ◽  
Edwin Hernández-Garzón ◽  
Marco Palombo ◽  
María-Angeles Carrillo-de Sauvage ◽  
Julien Flament ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Ex Vivo ◽  
Reactive Astrocytes ◽  
Resonance Spectroscopy ◽  
Morphological Alterations ◽  
Non Invasive ◽  
Diffusion Weighted ◽  
Fiber Radius

AbstractThe diffusion of brain intracellular metabolites, as measured using diffusion-weighted magnetic resonance spectroscopy in vivo, is thought to specifically depend on the cellular structure constraining them. However, it has never been established that variations of metabolite diffusion, e.g. as observed in some diseases, could indeed be linked to alterations of cellular morphology. Here we demonstrate, in a mouse model of reactive astrocytes, that advanced diffusion-weighted magnetic resonance spectroscopy acquisition and modeling techniques enable non-invasive detection of reactive astrocyte hypertrophy (increased soma radius, increased fiber radius and length), as inferred from variations of myo-inositol diffusion, and as confirmed by confocal microscopy ex vivo. This establishes that specific alterations of intracellular metabolite diffusion can be measured and related to cell-specific morphological alterations. Furthermore, as reactive astrocytes are a hallmark of many brain pathologies, this work opens exciting perspectives for neuroscience and clinical research.

scholarly journals BIMG-08. DEUTERIUM MAGNETIC RESONANCE SPECTROSCOPY USING 2H-PYRUVATE ALLOWS NON-INVASIVE IN VIVO IMAGING OF TERT EXPRESSION IN BRAIN TUMORS

2021 ◽  
Vol 3 (Supplement_1) ◽  
pp. i2-i2
Author(s):  
Georgios Batsios ◽  
Celine Taglang ◽  
Meryssa Tran ◽  
Anne Marie Gillespie ◽  
Joseph Costello ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
In Vivo Imaging ◽  
Lactate Production ◽  
Telomere Maintenance ◽  
Resonance Spectroscopy ◽  
Low Grade ◽  
Non Invasive ◽  
Tert Expression

Abstract Telomere shortening constitutes a natural barrier to uncontrolled proliferation and all tumors must find a mechanism of maintaining telomere length. Most human tumors, including high-grade primary glioblastomas (GBMs) and low-grade oligodendrogliomas (LGOGs) achieve telomere maintenance via reactivation of the expression of telomerase reverse transcriptase (TERT), which is silenced in normal somatic cells. TERT expression is, therefore, a driver of tumor proliferation and, due to this essential role, TERT is also a therapeutic target. However, non-invasive methods of imaging TERT are lacking. The goal of this study was to identify magnetic resonance spectroscopy (MRS)-detectable metabolic biomarkers of TERT expression that will enable non-invasive visualization of tumor burden in LGOGs and GBMs. First, we silenced TERT expression by RNA interference in patient-derived LGOG (SF10417, BT88) and GBM (GS2) models. Our results linked TERT silencing to significant reductions in steady-state levels of NADH in all models. NADH is essential for the conversion of pyruvate to lactate, suggesting that measuring pyruvate flux to lactate could be useful for imaging TERT status. Recently, deuterium (2H)-MRS has emerged as a novel, clinically translatable method of monitoring metabolic fluxes in vivo. However, to date, studies have solely examined 2H-glucose and the use of [U-2H]pyruvate for non-invasive 2H-MRS has not been tested. Following intravenous injection of a bolus of [U-2H]pyruvate, lactate production was higher in mice bearing orthotopic LGOG (BT88 and SF10417) and GBM (GS2) tumor xenografts relative to tumor-free mice, suggesting that [U-2H]pyruvate has the potential to monitor TERT expression in vivo. In summary, our study, for the first time, shows the feasibility and utility of [U-2H]pyruvate for in vivo imaging. Importantly, since 2H-MRS can be implemented on clinical scanners, our results provide a novel, non-invasive method of integrating information regarding a fundamental cancer hallmark, i.e. TERT, into glioma patient management.

scholarly journals Introduction to in vivo31P magnetic resonance spectroscopy of (human) skeletal muscle

1999 ◽  
Vol 58 (4) ◽  
pp. 861-870 ◽  
Author(s):  
A. Heerschap ◽  
C. Houtman ◽  
H. J. A. in 't Zandt ◽  
A. J. van den Bergh ◽  
B. Wieringa
Keyword(s):  
Skeletal Muscle ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Current Status ◽  
Resonance Spectroscopy ◽  
Biochemical Processes ◽  
Non Invasive ◽  
Introductory Overview ◽  
Muscle Biochemistry

31P magnetic resonance spectroscopy (MRS) offers a unique non-invasive window on energy metabolism in skeletal muscle, with possibilities for longitudinal studies and of obtaining important bioenergetic data continuously and with sufficient time resolution during muscle exercise. The present paper provides an introductory overview of the current status of in vivo31P MRS of skeletal muscle, focusing on human applications, but with some illustrative examples from studies on transgenic mice. Topics which are described in the present paper are the information content of the 31P magnetic resonance spectrum of skeletal muscle, some practical issues in the performance of this MRS methodology, related muscle biochemistry and the validity of interpreting results in terms of biochemical processes, the possibility of investigating reaction kinetics in vivo and some indications for fibre-type heterogeneity as seen in spectra obtained during exercise.

scholarly journals Non-Invasive Prediction of IDH Mutation in Patients with Glioma WHO II/III/IV Based on F-18-FET PET-Guided In Vivo 1H-Magnetic Resonance Spectroscopy and Machine Learning

Cancers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3406
Author(s):  
Elisabeth Bumes ◽  
Fro-Philip Wirtz ◽  
Claudia Fellner ◽  
Jirka Grosse ◽  
Dirk Hellwig ◽  
...  
Keyword(s):  
Machine Learning ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Support Vector ◽  
Resonance Spectroscopy ◽  
Idh Mutation ◽  
1H Mrs ◽  
1H Magnetic Resonance Spectroscopy ◽  
Non Invasive

Isocitrate dehydrogenase (IDH)-1 mutation is an important prognostic factor and a potential therapeutic target in glioma. Immunohistological and molecular diagnosis of IDH mutation status is invasive. To avoid tumor biopsy, dedicated spectroscopic techniques have been proposed to detect D-2-hydroxyglutarate (2-HG), the main metabolite of IDH, directly in vivo. However, these methods are technically challenging and not broadly available. Therefore, we explored the use of machine learning for the non-invasive, inexpensive and fast diagnosis of IDH status in standard 1H-magnetic resonance spectroscopy (1H-MRS). To this end, 30 of 34 consecutive patients with known or suspected glioma WHO grade II-IV were subjected to metabolic positron emission tomography (PET) imaging with O-(2-18F-fluoroethyl)-L-tyrosine (18F-FET) for optimized voxel placement in 1H-MRS. Routine 1H-magnetic resonance (1H-MR) spectra of tumor and contralateral healthy brain regions were acquired on a 3 Tesla magnetic resonance (3T-MR) scanner, prior to surgical tumor resection and molecular analysis of IDH status. Since 2-HG spectral signals were too overlapped for reliable discrimination of IDH mutated (IDHmut) and IDH wild-type (IDHwt) glioma, we used a nested cross-validation approach, whereby we trained a linear support vector machine (SVM) on the complete spectral information of the 1H-MRS data to predict IDH status. Using this approach, we predicted IDH status with an accuracy of 88.2%, a sensitivity of 95.5% (95% CI, 77.2–99.9%) and a specificity of 75.0% (95% CI, 42.9–94.5%), respectively. The area under the curve (AUC) amounted to 0.83. Subsequent ex vivo 1H-nuclear magnetic resonance (1H-NMR) measurements performed on metabolite extracts of resected tumor material (eight specimens) revealed myo-inositol (M-ins) and glycine (Gly) to be the major discriminators of IDH status. We conclude that our approach allows a reliable, non-invasive, fast and cost-effective prediction of IDH status in a standard clinical setting.

scholarly journals Diffusion-weighted magnetic resonance spectroscopy enables cell-specific monitoring of astrocyte reactivity in vivo

NeuroImage ◽  
2019 ◽  
Vol 191 ◽  
pp. 457-469 ◽  
Author(s):  
Clémence Ligneul ◽  
Marco Palombo ◽  
Edwin Hernández-Garzón ◽  
María-Angeles Carrillo-de Sauvage ◽  
Julien Flament ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Resonance Spectroscopy ◽  
Diffusion Weighted

scholarly journals Proton Magnetic Resonance Spectroscopy Characterization of Rathke’s Cleft Cysts (RCCs): Relevance to the Differential Diagnosis of Pituitary Adenomas and RCCs

Cancers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 360
Author(s):  
Omkar B. Ijare ◽  
Martyn A. Sharpe ◽  
David S. Baskin ◽  
Kumar Pichumani
Keyword(s):  
Differential Diagnosis ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Pituitary Adenomas ◽  
Ex Vivo ◽  
Medical Professionals ◽  
Resonance Spectroscopy ◽  
Rathke's Cleft Cysts ◽  
Rathke's Cleft

Background: Rathke’s Cleft Cysts (RCCs) are rare epithelial cysts arising from remnants of the Rathke pouch in the pituitary gland. A subset of these lesions enlarge and produce a mass effect with consequent hypopituitarism, and may result in visual loss. Moreover, some RCCs with a high intra-cystic protein content may mimic cystic pituitary adenoma, which makes their differential diagnosis ambiguous. Currently, medical professionals have no definitive way to distinguish RCCs from pituitary adenomas. Therefore, preoperative confirmation of RCCs would be of help to medical professionals for the management and proper surgical decision making. The goal of this study is to identify molecular markers in RCCs. Methods: We characterized aqueous and chloroform extracts of surgically resected RCCs and pituitary adenomas using ex vivo 1H NMR spectroscopy. Results: All RCCs exclusively showed the presence of mucopolysaccharides which are glycosaminoglycans (GAGs) made up of disaccharides of aminosugars and uronic sugars. Conclusion: GAGs can be used as metabolite marker for the detection of RCCs and this knowledge will lay the groundwork for the development of a non-invasive, in vivo magnetic resonance spectroscopy methodology for the differential diagnosis of RCCs and pituitary adenomas using clinical MRI scanners.

In Vivo and Ex Vivo Magnetic Resonance Spectroscopy in the Characterization of Hemangioblastoma Cyst Fluid

2014 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Girolamo Crisi ◽  
Silvano Filice ◽  
Thelma A. Pertinhez ◽  
Elisa Ventura ◽  
Franco Servadei
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Ex Vivo ◽  
Cyst Fluid ◽  
Resonance Spectroscopy

Magnetic Resonance Spectroscopy and its Applications in Psychiatry

2002 ◽  
Vol 36 (1) ◽  
pp. 31-43 ◽  
Author(s):  
Gin S. Malhi ◽  
Michael Valenzuela ◽  
Wei Wen ◽  
Perminder Sachdev
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Brain Regions ◽  
Response To Treatment ◽  
Resonance Spectroscopy ◽  
Biochemical Basis ◽  
Non Invasive ◽  
Investigative Technique ◽  
Neurochemical Changes

Objective: This paper briefly describes neuroimaging using magnetic resonance spectroscopy (MRS) and provides a systematic review of its application to psychiatric disorders. Method: A literature review ( Index Medicus/ Medline) was carried out, as well as a review of other relevant papers and data known to the authors. Results: Magnetic resonance spectroscopy is a complex and sophisticated neuroimaging technique that allows reliable and reproducible quantification of brain neurochemistry provided its limitations are respected. In some branches of medicine it is already used clinically, for instance, to diagnose tumours and in psychiatry its applications are gradually extending beyond research. Neurochemical changes have been found in a variety of brain regions in dementia, schizophrenia and affective disorders and promising discoveries have also been made in anxiety disorders. Conclusions: Magnetic resonance spectroscopy is a non-invasive investigative technique that has provided useful insights into the biochemical basis of many neuropsychiatric disorders. It allows direct measurement, in vivo, of medication levels within the brain and has made it possible to track the neurochemical changes that occur as a consequence of disease and ageing or in response to treatment. It is an extremely useful advance in neuroimaging technology and one that will undoubtedly have many clinical uses in the near future.

Sign in / Sign up

Export Citation Format

Share Document